1. Field of the Invention
Embodiments of the present invention relate generally to Voice over Internet Protocol (VoIP) technology, and more particular to implementation of virtual multiple lines in a communication system.
2. Description of Background Art
In a public switched telephone network (PSTN), an initiating phone connects to a circuit switch and the PSTN via a first plain old telephone service (POTS) line. Similarly, a destination phone connects to the circuit switch and the PSTN via a second POTS line. As such, the circuit switch electrically connects the initiating phone to the destination phone over the PSTN. The electrical connection is maintained for an entire duration of a phone call between the initiating phone and the destination phone. This electrical connection in the PSTN is commonly referred to as “circuit switched.” However, a problem with the PSTN is that because much of a conversation is silence, maintaining the electrical connection for the duration of the phone call wastes available bandwidth in the circuit switch.
A POTS line can only carry one active phone call at a time. An active call is a call where the parties active in the call can communicate. To be able to place additional phone calls using the same phone number allocated to the first POTS line the PSTN provider must install additional POTS lines at the customer premises.
Voice over Internet Protocol (VoIP) is a technology that permits phone calls to be carried over the Internet as opposed to over the PSTN. In VoIP, a device known as an analog telephone adapter (ATA) or media gateway serves as an interface between an analog phone and the packet-based Internet. In operation, an initiating ATA converts analog signals from an initiating phone into packets using a voice codec. To receive an incoming call at the destination phone, a destination ATA receives packets into a buffer and uses the same codec to convert the packets back into analog signals. The ATA may be a stand-alone device or may be incorporated into another device such as a cordless phone base station or broadband modem.
Conventionally, ATAs provide VoIP functionality via a connection to a broadband modem, such as through a cable modem or a digital subscriber line (DSL) connection to the Internet. Broadband refers to communications in which multiple messages or channels may be carried simultaneously over the same transmission medium. A broadband network is any network capable of providing broadband services (e.g., a network supporting digital traffic). VoIP services are generally provided through an Internet Telephony Service Provider (ITSP). In many instances, the ITSP strives to emulate the behavior and reliability of the PSTN while offering a lower cost for delivering the service and/or increased functionality.
For many VoIP services offered for residential use, a single ATA is provided which delivers the VoIP services. As such, there is a limited ability to offer VoIP services to multiple phones in the residence. Instead, the user may be encouraged to connect a multi-station cordless phone system to the FXS port of the ATA so that the benefits of the VoIP service can be enjoyed on multiple phones in the residence. This approach, however, carries with it many limitations. For example, such cordless phone systems require AC power, which results in the phone system ceasing to function in an event of a power outage. Another disadvantage with using a single ATA is that a user may lose use of existing phones since the ATA only provides a single FXS port located at just one location in the home. Furthermore, audio quality of most cordless systems is lower than wired telephone systems. Yet another disadvantage is that cordless handsets have limited or no user interface to facilitate implementation of new features.
In alternative embodiments, the user may disconnect the home wiring from the PSTN network and drive the home wiring from the FXS port of the ATA. This alternative, however, does not work for users who receive their broadband service via a digital subscriber line (DSL) since a connection to the PSTN infrastructure is required to deliver the DSL service to the residence. Physically disconnecting the home wiring from the PSTN wiring of the local phone carrier also requires a level of technical skill and knowledge that is not common among typically users.
A further limitation of most VoIP services is that connecting multiple simultaneous calls into or out of the residence requires multiple ATAs with separate phone numbers and separate phones or phone systems (e.g., the cordless phone system). This limits flexibility for the user who may have multiple people living in a residence who may wish to hold a plurality of phone conversations at the same time.
Where multiple phones are served by a single ATA, the user is limited to placing or receiving a single phone call at any one time. In a residence where a plurality of people may need to use the phone, this limitation can lead to significant inconvenience. Therefore, a need exists in industry to address some of the aforementioned deficiencies and inadequacies.